Neighbor-against-neighbor legal battles over airspace, town councils' grid-capacity concerns and myriad other local solar permitting and access problems continue to frustrate PV installers and would-be customers. Making matters worse are the inconsistent and often confusing permit rules in the U.S. for installing solar arrays.

"There's just a hodgepodge of law," Troy Rule, an associate professor at the University of Missouri School of Law, tells Solar Industry.

With his new project, Rule hopes to put an end to this legal patchwork and remove a major market barrier for solar. Thanks to a $52,800 grant from industry group SolarTech (a portion of a $2.5 million award that SolarTech recently received from the U.S. Department of Energy), he is developing a set of standardized model ordinances and statutes for local governments.

As the number of residential and commercial installations in the U.S. increases, the issue of solar rights has emerged as one of the thorniest legal problems - and a primary issue that Rule plans to tackle.

Currently, a few states have a solar rights rule requiring that residents do not impede operation of a neighbor's solar installation - such as by planting a large tree or building a sunlight-blocking home addition. Others require the solar array owner to sell an access easement, while others have no laws on the issue.

Rule says his model ordinance will adopt what he considers the fairest approach. "How do you create a rule that incentivizes the parties involved to use the airspace for its highest-value use? That's the ultimate goal," he explains.

Iowa's approach to solar rights strikes the right balance, according to Rule. "If you put up solar panels, you do not automatically obtain rights in your neighbor's airspace," he explains. "You must go to the neighbor and negotiate a voluntary easement that is validated as an enforceable document.

"But if your neighbor is unwilling to work with you, then you can force the neighbor to sell [the easement] to you at its fair-market value," he continues. "The neighbor is compensated, and solar users are guaranteed to get access."

Naturally, in a congested urban area - where airspace is at a premium - that fair-market value may be prohibitively high. Rule, whose previous legal-practice focus included both the real estate and wind power sectors, says that in downtown Manhattan, for instance, giving up airspace worth millions for an individual property owner's solar easement would not be in the public's best interest.

"One of the problems with solar access is that some avid supporters of it forget that there are sometimes better uses of airspace than to preserve solar access," he points out.

This goal of increasing solar energy deployment in a manner that provides the maximum public benefit is also evident in Rule's proposed approach to local ordinances for new housing developments.

"If a developer wants to put in 400 or 500 units, the [town's] concern will be limited grid capacity," he says, adding that these grid concerns have become particularly acute in Arizona and other Southwest states. "These communities are also trying to promote solar energy."

One solution, according to Rule, is to make the housing developer's project approval contingent on installing a specified amount of solar capacity - e.g., by setting aside property for a collective solar facility to offset grid demand or installing a large array on a new school being built as part of the development.

This type of requirement - known as a development exaction - is not unprecedented, he adds. Housing developers are commonly required to donate set fees to local school systems, police departments and other municipal service providers in order to offset their impact.

Developers commonly pass along the costs of exactions to home buyers - which ultimately helps the entire community by increasing the values of both the new properties and existing homes.

Of course, the solar market would benefit from increased project flow. For this reason, Rule urges installers and other stakeholders to lobby their local governments to adopt this model ordinance, in particular, once it is introduced.

Once all of Rule's ordinances and statutes are finalized, local governments will be provided with the completed models, which they may or may not opt to incorporate into their own codes. Because of the individual needs of each city and town, each ordinance is designed for flexibility, with many optional provisions built into it, he notes.

Model ordinances and statutes, as a whole, are not mandatory. "The idea is to make it easier for local governments to digest what they might want to do and then administer," Rule explains. "It's optional. But it should be helpful."

(Please address all comments regarding this article to Jessica Lillian, editor of Solar Industry, at jlillian@solarindustrymag.com.)